For more specific statistics on Promotion Codes usage go to Admin Panel > Reports > Promotions Usage:
On the newly opened page select the needed period and you will see the following form:
On this page you can check:
Promotion Code - what promotion codes were used;
Discount Type - what discount type a promotion code provided - percentage or fixed monetary amount;
Usage Count - number of time a codes was applied.
Note: A code is considered as applied after an invoice with the discount provided by this code was created in the system. Promotion code is not considered as applied when a user enters it in shopping cart and clicks 'Apply'.
Discount Value - Indicates what discount this code was supposed to provide.
Discount Amount - Indicates the whole sum of discount provided by this code within selected period.
Sales Subtotal - Indicates the total sum of sales without discount.
Sale Total - Indicates the total sum of sales with discount.